• 한국터널지하공간학회 논문집
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• 제18권1호
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• pp.53-60
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• 2016

본 논문은 터널 유지관리계측의 압력 관리기준치 설정에 대한 연구로 계측 초기에 설정된 지하철계측 초기 관리기준치를 토대로 서울지하철 6,7,9호선 8개 대표단면의 터널 콘크리트라이닝의 토압과 간극수압에 대하여 약 5년에 걸친 계측 실적을 분석하고, 국외 계측관리기준을 비교하여 향후 터널 유지관리계측에 적용할 압력 계측관리기준치 설정에 대한 연구를 수행하였다. 연구결과 향후에 터널에 적용할 유지관리계측의 압력 관리기준치는 국내적용 계측관리기준치와 국외적용 계측관리기준치 분석결과를 비교하여 안전단계는 허용압력의 60%, 주의단계는 허용압력의 80%, 정밀분석단계는 허용압력의 100%로 실무에서 쉽게 적용할 수 있는 절대치에 의한 계측관리방법을 제안하였다.

• Nuclear Engineering and Technology
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• 제51권6호
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• pp.1681-1688
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• 2019

In accordance with ASME Boiler and Pressure Vessel (B&PV) Code Sec.XI Appendix. G, a postulated crack is located at the beltline of a reactor pressure vessel because the neutron flux at the beltline is higher than elsewhere. This means that the distance between the core and the semi-spherical bottom head is longer than the distance between the core and the cylindrical beltline. However, several Small and Medium sized Reactors have bottom heads with diverse shapes, including dished or semi-elliptical shapes, to satisfy the requirement and performance. So, the aim of this paper is to evaluate the effect of crack location on Pressure-Temperature limit curve. To do this, two types of postulated crack location, such as beltline and semi-elliptical bottom head, were adopted to derive the Pressure-Temperature limit curve. Also, parametric studies for neutron flux, crack shape and so on were performed. As a result, core critical temperature of semi-elliptical bottom head is found to higher than that of beltline even when they have same values of thickness and neutron flux. This result will be useful to enhance the understanding of Pressure-Temperature limit curve.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.901-910
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• 2021

KHNP recently has obtained the approval for the commercialization of the modified 37-element (or 37 M) fuel bundle and now is loading the 37 M fuel bundles in CANDU-6 reactors in KOREA. One of the main issues for approval was the burnup limit. Due to CANDU design and neutronic characteristics, there was no specific burnup restriction of a fuel bundle. The absence of a burnup limit does not mean that a fuel bundle can stay in the CANDU reactor without a time limit. However, the regulator requested traditional design values as well as the burnup limit reflecting the computer code uncertainty. The method for the PWR burnup limit was not applied to the CANDU fuel bundle. Since there was no approved methodology to build the burnup limit with uncertainties, KHNP introduced a Monte-Carlo method coupled with a 95/95 approach to determine the conservative burnup limit from the viewpoint of the centerline temperature, internal pressure, strain measurement deviation. Moreover, to consider the uncertainties of various computing models, a converted power uncertainty was introduced. This paper presents the methodology and puts forward the limits on burnup, evaluated for each of the existing and modified fuel bundles, in consideration of the pressure tube aging condition.

• Journal of Preventive Medicine and Public Health
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• 제7권2호
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• pp.395-401
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• 1974

In order to figure out the normal range, lower limit of hypertension and upper limit of hypotension of the blood pressure of Korean, authors had measured blood pressure according to Korotkow's method for 31,897 healthy persons as samples who were occupied different levels of the social class except cases who would seem to be the essential hypertension and had the diseases affecting to secondary hypertension. A following conclusion was induced by actual measurement and statistical reasoning. 1. The normal range and limits of hypo- and hypertension by sex and age groups of Korean were demonstrated in Table 1 and Figure 1. 2. The more aging the higher value of blood pressure in both sexes, especially women rather than men and systolic as to diastolic. 3. Generally, blood pressure values of female were lower than male, after 55 years of age, however, the crossing phenomenon was recognizable. 4. To settle the normal and abnormal ranges of the blood pressure of Korean, it was attempted that $M{\pm}1.282{\sigma}$ as normal range, $M+2{\sigma}$ as lower limit of hypertension and $M-2{\sigma}$ as upper limit of hypotension were calculated, and regression lines were drawn to adjust the biological variables and derive continuity from each age class. (Fig. 2 and 3) 5. The blood pressure levels were becoming elevated as to getting increased of the body weight, particularly diastolic value at 40-49 age group in male and systolic value at 30-39 age group in female.

• 산업기술연구
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• 제28권B호
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• pp.71-79
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• 2008

Reports about coefficients of consolidation in horizontal direction of marine clays located at seven different sites on western and southern coast area in Korea were reviewed and characteristics of them were investigated. As results of analyses, for relation between the depth of ground and coefficients, any trend and correlation between them can not be found since they are more influenced by the nature of geological formation rather than the depth of ground. Dissipation time t50, one of important factors in estimating value of coefficient of consolidation in horizontal direction, was found to be quite related to them. For the correlation between the maximum pore pressure developed and coefficients, coefficient of consolidation in the horizontal direction tend to decrease with increase of the maximum pore pressure whereas the ground water level or static pore pressure do not have any specific correlation with those coefficients. Values of coefficient tends to increase with values of liquid limit, plastic limit and plastic index and thus they are found to be directly influenced by the contents of fines. Values of coefficient of consolidation in horizontal direction are also increased with increases of permeability in horizontal direction and coefficient of consolidation in vertical direction. They were highly correlated between coefficient of consolidation and permeability in horizontal direction while values of coefficient of consolidation in horizontal direction have a relatively low correlation with values of coefficient of consolidation in horizontal direction. Sometimes, coefficient of consolidation in horizontal direction obtained from field tests were estimated 2-3 times greater than those from laboratory tests.

• 한국콘텐츠학회논문지
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• 제18권11호
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• pp.348-352
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• 2018

BioRescue($RMIng{\acute{e}}nierie$, Marseille, France)는 대상자가 일어서거나 앉을 때 동적과 정적인 균형을 평가하기 위해 사용하는 장비이다. 이전부터 다양하게 사용되고 있지만 이 장비에 대한 명확한 신뢰도에 대한 연구는 아직 부족한 상태이다. 본 논문은 균형 능력 측정을 위한 BioRescue의 측정자내와 측정자간 신뢰도를 측정했다. 이 연구의 대상자는 34명의 건강한 대상자들과 2명의 물리치료사 평가자들로 구성되었다. BioRescue는 발지표(면적과 압력), 롬버그 검사, 안정성 검사로 구성되어 있다. 발지표의 면적과 안정성 검사는 모든 방향에서 ICC값이 0.60 이상으로 나왔다. 하지만 발지표의 압력과 롬버그 검사는 모든 방향에서 ICC값이 0.60 이하로 나왔다. BioRescue는 균형검사 시 발지표의 면적과 안정성 검사에서 높은 신뢰도를 나타냈다. 하지만, 발지표의 압력과 롬버그 검사의 수치에서 숙련자와 비숙련자의 차이를 보이기 때문에 장비의 정확성을 위해 숙련이 필요하다.

• 한국안전학회지
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• 제24권5호
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• pp.28-33
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• 2009

The thermochemical parameters for safe handling, storage, transport, operation and process design of flammable substances are explosion limit, flash point, autoignition temperatures(AITs), minimum oxygen concentration(MOC), heat of combustion etc.. Also it is necessary to know explosion limit at high temperature and pressure. For the safe handling of benzene, lower explosion limit(LEL) at $25^{\circ}C$, the temperature dependence of the explosion limits and flash point were investigated. And the AITs for benzene were experimented. By using the literatures data, the lower and upper explosion limits of benzene recommended 1.3 vol% and 8.0 vol%, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for benzene, and the experimental AIT of benzene was $583^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of benzene is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.343-350
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• 2002

The structural stability of pressure housing of SMART CEDM forming pressure boundary must be evaluated. In this paper, the stress and thermal analyses of the upper pressure housing of CEDM are performed for design pressure, hydraulic test pressure and thermal loading. Finite element and boundary condition were generated from the model which is made by I-DEAS program and the stress and thermal analyses were performed by ANSYS Program. The upper Pressure housing was analysed using 2D axisymmetric model because it is symmetry about an axis. The stress values obtained by analysis were compared with the stress intensity limit of ASME and KEPIC MNB standard.

• 한국지반공학회지:지반
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• 제12권2호
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• pp.33-42
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• 1996

포항지역 이암의 풍화가 slaking및 흡수팽창에 기인됨을 인식하고, 3개 지점에서 채취한 이암시료를 대상으로 광물성분, slaking 및 팽창시험을 수행하였다. 또한 풍화로 인하여 열화된 이암의 잔류전단강도를 측정하였는데 역전식 잔류전단시험을 채택하였다. 시험결과, 각 이암시료의 광물성분은 석영과 점토광물이 대종을 이루고 있으며, 두번째 slaking cycle에서의 slake내구성 지수는 71%~96% 범위이고 암석분말시료의 액성한계가 높을수록 내구성지수는 떨어지는 경향을 보인다. 또한 팽창압력의 크기도 액성한계가 높은 시료에서 월등히 큰 9.4kg10m2로 측정되었으며, 이러한 경향은 팽창변형률(최대치 :33.5%)에서도 마찬가지로 나타났다. 이암의 잔류전 단강도는 건습반복회수가 증가될수록 감소되어 5회 건습반복후의 잔류강도는 c,=0.24kg/cm2, f,=28$^{\circ}$로 측정되었다. 그리고 습윤상태에서 이암-이암 경계면을 따라 측정한 잔류강도가 최저값인 cr=0 and or=21.5$^{\circ}$로 나타났다.

• 한국화재소방학회논문지
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• 제15권3호
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• pp.14-20
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• 2001

인화점은 가연성물질의 화재 및 폭발의 잠재위험성를 결정하는 데 가장 중요한 기초적인 특성치 가운데 하나이다. 인화점의 구분은 혼합용제를 구성하는 가연성액체를 안전하게 취급하기 위해서 매우 중요하다. 모든 인화점 거동의 기초는 증기압과 폭발한계이다. 가연성혼합용제의 인화점은 라울의 법칙, 달톤의 법칙, 르샤틀리에 법칙 그리고 활동도계수 모델을 사용함으로서 계산할 수 있다. 본 연구에서는 가연성 3성분계의 하부인화점의 문헌값을 라울의 법칙과 MRSM 모델에 의해 계산된 값과 비교하였다. 3성분계의 하부인화점의 자료는 라울의 법칙과 MRSM 모델에 의해 예측된 값과 거의 일치하였다. 제시한 방법론에 의해 가연성혼합용제의 인화점 실험자료의 신뢰도를 평가하는 것이 가능하다.